Every spring we get the same call from Troutville to Rocky Mount: the deck looks tired, a board is soft, and the homeowner wants to know whether it's a repair or a rebuild. The answer lives underneath, not on top.
Start with the ledger, the board that attaches the deck to the house. If it's rotted, pulling away, or fastened with nails instead of lag bolts or structural screws, the deck is a safety issue regardless of how the surface looks. That's a rebuild-the-connection job at minimum.
Then check the posts and beams. Push a screwdriver into the base of each post and into the beam near any joint. Soft wood means rot has moved past the surface. One or two bad posts can be sistered or replaced. Rot across most of the frame means the surface boards you'd save aren't worth saving.
If the frame is sound, replacing decking and railings is a straightforward job that gives you a new-looking deck at a fraction of the cost. It's also the moment to switch to composite if you're done staining, and to add lighting on the stairs while the electrician is already out.
If the frame is gone, a new deck built on proper footings below frost depth, with flashed ledgers and code-compliant railings, will outlast the old one by decades. Either way, get the assessment in writing so you're deciding on facts, not on how the boards look after a pressure wash.